U.S. patent application number 13/197202 was filed with the patent office on 2012-12-06 for switch for pneumatic tool.
Invention is credited to Hsin-Chi Chen.
Application Number | 20120305819 13/197202 |
Document ID | / |
Family ID | 47173441 |
Filed Date | 2012-12-06 |
United States Patent
Application |
20120305819 |
Kind Code |
A1 |
Chen; Hsin-Chi |
December 6, 2012 |
SWITCH FOR PNEUMATIC TOOL
Abstract
Used in a pneumatic tool having an air intake passage and a gas
control member set in the air intake passage, a switch is disclosed
to include a valve seat set in the air intake passage and movable
into contact with or away from the gas control member and defining
an air hole, and a valve rod inserted through the air hole of the
valve seat and biasable to stop a positioning portion thereof
against the air hole or to move the positioning portion away from
the air hole. When the positioning portion of the valve rod is
stopped against the valve seat and the valve seat is stopped
against the gas control member, the air intake passage is blocked.
When the valve rod is biased relative to the valve seat, the
positioning portion is moved away from the air hole of the valve
seat for allowing a compressed gas to pass through the air hole,
and when the valve rod is biased further to carry the valve seat
away from the gas control member, the compressed gas is allowed to
pass between the valve seat and the gas control member.
Inventors: |
Chen; Hsin-Chi; (Taichung
City, TW) |
Family ID: |
47173441 |
Appl. No.: |
13/197202 |
Filed: |
August 3, 2011 |
Current U.S.
Class: |
251/213 |
Current CPC
Class: |
B25F 5/00 20130101 |
Class at
Publication: |
251/213 |
International
Class: |
F16K 31/44 20060101
F16K031/44 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 2, 2011 |
TW |
100119399 |
Claims
1. A switch used in a pneumatic tool comprising an air intake
passage and a gas control member set in said air intake passage,
the switch comprising: a valve seat defining an air hole, said
valve seat being set in said air intake passage and movable
relative to said air intake passage into contact with or away from
said gas control member; and a valve rod comprising a positioning
portion, said valve rod being inserted through said air hole of
said valve seat and biasable relative to said valve seat to stop
said positioning portion against said air hole or to move said
positioning portion away from said air hole; wherein when said
positioning portion of said valve rod is stopped against said valve
seat and said valve seat is stopped against said gas control
member, said air intake passage is blocked; when said valve rod is
biased relative to said valve seat, said positioning portion is
moved away from said air hole of said valve seat for allowing a
compressed gas to pass through said air hole, and when said valve
rod is biased further to carry said valve seat away from said gas
control member, said compressed gas is allowed to pass between said
valve seat and said gas control member.
2. The switch as claimed in claim 1, wherein said valve seat
comprises an annular seat base, said annular seat base comprising
at least one groove located on an inside wall thereof; said air
hole is formed of the center and said at least one groove of said
annular seat base.
3. The switch as claimed in claim 1, wherein said valve seat
comprises a shoulder disposed in a coaxial manner relative to said
air hole; said positioning portion of said valve rod is stoppable
against said shoulder.
4. The switch as claimed in claim 1, wherein said positioning
portion of said valve rod is attached with a seal member.
5. The switch as claimed in claim 1, wherein said valve seat
further comprises at least one protruding portion located on the
periphery thereof for stopping against a peripheral wall of said
air intake passage.
6. The switch as claimed in claim 1, wherein said seal member is
selected from the group of O-ring, rubber gasket ring and flexible
materials.
7. The switch as claimed in claim 1, further comprising a spring
member set between said valve rod and an inside wall of said air
intake passage.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to pneumatic tools and more
particularly, to a switch for use in a pneumatic tool.
[0003] 2. Description of the Related Art
[0004] A pneumatic tool or air tool is a tool driven by a gas,
usually compressed air supplied by a gas compressor for rotating a
motor at a high speed to move a transmission mechanism in producing
a high torque output for fastening or unfastening mechanical
members.
[0005] However, when using the aforesaid pneumatic tool to provide
a low torque output for a pre-fastening operation, the user must
switch a speed control mechanism of the pneumatic tool to a low
speed mode and then press the trigger. This operation manner is
inconvenient and not easy to control. Further, when the gas
pressure of the pneumatic tool is high during operation, the user
must apply much effort to press down the trigger. Thus, the user is
inclined to get tired easily, affecting the working efficiency.
SUMMARY OF THE INVENTION
[0006] The present invention has been accomplished under the
circumstances in view. It is the main object of the present
invention to provide a switch for pneumatic tool, which can control
the revolving speed of the pneumatic tool in a stepped manner,
facilitating the operation of the pneumatic tool to fit different
applications or requirements and enhancing the working
efficiency.
[0007] To achieve this and other objects of the present invention,
a switch is used in a pneumatic tool having an air intake passage
and a gas control member set in the air intake passage. The switch
comprises a valve seat set in the air intake passage and movable
into contact with or away from the gas control member and defining
an air hole, and a valve rod inserted through the air hole of the
valve seat and biasable to stop a positioning portion thereof
against the air hole or to move the positioning portion away from
the air hole. When the positioning portion of the valve rod is
stopped against the valve seat and the valve seat is stopped
against the gas control member, the air intake passage is blocked.
When the valve rod is biased relative to the valve seat, the
positioning portion is moved away from the air hole of the valve
seat for allowing a compressed gas to pass through the air hole,
and when the valve rod is biased further to carry the valve seat
away from the gas control member, the compressed gas is allowed to
pass between the valve seat and the gas control member.
[0008] Other advantages and features of the present invention will
be fully understood by reference to the following specification in
conjunction with the accompanying drawings, in which like reference
signs denote like components of structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic sectional view illustrating a switch
installed in a pneumatic tool in accordance with the present
invention.
[0010] FIG. 2 is an elevational exploded view of the switch for
pneumatic tool in accordance with the present invention.
[0011] FIG. 3 is a top view of the valve seat of the switch for
pneumatic tool in accordance with the present invention.
[0012] FIG. 4 is a schematic applied view of the present invention,
illustrating the valve rod biased relative to the valve seat.
[0013] FIG. 5 is another schematic applied view of the present
invention, illustrating the valve seat moved with the valve rod
away from the gas control member of the pneumatic tool.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to FIG. 1, a switch 10 in accordance with the
present invention is shown used in a pneumatic tool 40 comprising
an air intake passage 42 and a gas control member 44 set in the air
intake passage 42. The gas control member 44 defines a center
through hole 46. When the gas control member 44 is set in the air
intake passage 42, the center through hole 46 is kept in
communication with the air intake passage 42. The switch 10
comprises a valve seat 20 and a valve rod 30.
[0015] Referring to FIGS. 2 and 3, the valve seat 20 comprises an
annular seat base 21. The annular seat base 21 comprises opposing
top wall 23 and bottom wall 24, and a plurality of grooves 22
equiangularly spaced around the inside wall thereof and extending
from the top wall 23 to the bottom wall 24. Thus, the center and
grooves 22 of annular seat base 21 form an air hole 25. The annular
seat base 21 further comprises a shoulder 26 located on the bottom
wall 24 in a coaxial manner relative to the air hole 25, and a
plurality of protruding portions 27 spaced around the periphery for
controlling tilting of the valve seat 20 in the air intake passage
42.
[0016] The valve rod 30 comprises a disk-like positioning portion
32 located on one end thereof. Further, a seal member 34 is
attached to the disk-like positioning portion 32 of the valve rod
30. The seal member 34 can be an O-ring or rubber gasket ring, or
any flexible member made of a flexible material. The diameter of
the valve rod 30 is slightly smaller than the inner diameter of the
annular seat base 21 of the valve seat 20. The valve rod 30 is
inserted upwardly through the air hole 25 of annular seat base 21,
and biasable relative to the valve seat 20 to stop the seal member
34 against the shoulder 26 of the valve seat 20 or to move the seal
member 34 away from the shoulder 26 of the valve seat 20.
[0017] When installing the switch 10 in the air intake passage 42
of the pneumatic tool 40, as shown in FIG. 1, set a spring member
45 between the positioning portion 32 of the valve rod 30 and an
inside wall of the air intake passage 42, enabling the spring
member 45 to impart an upward pressure to the valve rod 30 and the
valve seat 20 relative to the pneumatic tool 40 to force the top
wall 23 of the valve seat 20 against the gas control member 44 and
the seal member 34 against the shoulder 26 of the valve seat 20. At
this time, the center through hole 46 of the gas control member 44
and the air hole 25 of annular seat base 21 are sealed, stopping
the compressed gas of the pneumatic tool 40 from entering the air
intake passage 42.
[0018] Referring to FIG. 4, when the user presses a trigger 48 of
the pneumatic tool 40 to move a short distance, the trigger 48
biases the valve rod 30 through a small angle without moving the
valve seat 20, causing the seal member 34 to be moved away from the
shoulder 26 of the valve seat 20 for allowing a compressed gas from
a compressed gas source (not shown) to go through the grooves 22 of
the valve seat 20 and the center through hole 46 of the gas control
member 44 into the air intake passage 42. At this time, the flow
rate of the compressed gas passing through the air hole 25 of
annular seat base 21 for driving the pneumatic tool 40 is low, and
therefore the pneumatic tool 40 is rotated at a low speed,
facilitating screw bolt pre-fastening operation.
[0019] Referring to FIG. 5, when the user pressed down the trigger
48 to the limit, the triggers 48 biases the valve rod 30 through a
large angle, causing the valve rod 30 to move the valve seat 20
away from gas control member 44 for allowing the compressed gas to
go through the grooves 22 of the valve seat 20 and the center
through hole 46 of the gas control member 44 into the air intake
passage 42 at a high flow rate, and therefore the pneumatic tool 40
is rotated at a high speed, facilitating normal fastening or
unfastening operation.
[0020] As the valve rod 30 can steppedly bias the valve seat 20 at
first and then carry the valve seat 20 away from the gas control
member 44, the invention can control the flow rate of the applied
compressed gas passing through the air intake passage 42 to drive
the pneumatic tool 40 at a low speed or high speed to fit different
applications or operating requirements. Further, if the gas
pressure of the pneumatic tool 40 is high (for example, 13
kg/cm.sup.2) during operation, the stepped driving function of the
present invention enables the user to operate the pneumatic tool
with less effort, preventing fatigue and enhancing the working
efficiency.
[0021] Although a particular embodiment of the invention has been
described in detail for purposes of illustration, various
modifications and enhancements may be made without departing from
the spirit and scope of the invention. Accordingly, the invention
is not to be limited except as by the appended claims.
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